Atomic write command support in a solid state drive
View Patent ↗A method of performing an atomic write command in a data storage device comprising a volatile memory and a plurality of non-volatile memory devices configured to store a plurality of physical pages. The method may comprise storing data in a plurality of logical pages (L-Pages), each associated with a logical address. A logical-to-physical address translation map may be maintained in the volatile memory, and may be configured to enable determination of a physical location, within one or more of the physical pages, of the data referenced by each logical address. The data specified by a received atomic write command may be stored one or more L-Pages. Updates to the entry or entries in the translation map associated with the L-Page(s) storing the data specified by the atomic write command may be deferred until all L-Pages storing data specified by the atomic write command have been written in a power-safe manner.
1. A method comprising:
receiving an atomic write command;
storing, based on the atomic write command, data in one or more logical pages (L-Pages), wherein each L-Page among the one or more L-Pages is associated with a logical address;
generating a system journal (S-Journal) entry for each of the one or more L-Pages wherein each S-Journal entry comprises a first sequence number associated with the atomic write command;
determining, based on the S-Journal entries, whether all L-Pages are stored in a non-volatile memory; and
after a power loss event, in response to determining that all L-Pages are not stored in the non-volatile memory:
determining, based on the first sequence number, a minimum L-Page number, and a maximum L-Page number, a range of L-Page numbers;
for each L-Page number in the range of L-Page numbers, determining data in the L-Page associated with the L-Page prior to receiving the atomic write command; and
generating a copy command to store the data, for the L-Pages associated with the range of L-Page numbers, in the non-volatile memory.
2. The method of claim 1 , further comprising:
in response to determining that all L-Pages are stored in the non-volatile memory:
updating an entry in a logical-to-physical address translation map.
3. The method of claim 1 , further comprising:
for each of the one or more L-Pages, storing, in a data structure in a volatile memory, an entry that specifies a physical address in the non-volatile memory that is associated with the logical address of the L-Page.
4. The method of claim 1 , wherein each S-Journal entry associates one or more physical pages to the L-Page.
5. The method of claim 1 , further comprising:
storing a second sequence number in a power-safe memory.
6. The method of claim 5 , further comprising:
determining whether the first sequence number comprised in the S-Journal entry matches the second sequence number; and
in response to determining that the first sequence number matches the second sequence number:
determining that all L-Pages are not stored in the non-volatile memory.
7. The method of claim 5 , further comprising:
in response to determining that the first sequence number does not match the second sequence number:
determining that all L-Pages are stored in the non-volatile memory.
8. The method of claim 1 , further comprising:
for each L-Page stored in the non-volatile memory:
determining whether an L-Page number associated with the L-Page is less than a minimum L-Page number comprised in an entry in a data structure;
in response to determining that the L-Page number associated with the L-Page is less than the minimum L-Page number:
updating the minimum L-Page number comprised in the entry with the L-Page number associated with the L-Page, wherein the entry is associated with the first sequence number associated with the atomic write command;
determining whether the L-Page number associated with the L-Page is greater than a maximum L-Page number comprised in the entry; and
in response to determining that the L-Page number associated with the L-Page is greater than the maximum L-Page number:
updating the maximum L-Page number comprised in the entry with the L-Page number associated with the L-Page.
9. The method of claim 1 , further comprising:
in response to determining that all L-Pages are not stored in the non-volatile memory:
deferring an update to an entry in a logical-to-physical address translation map until all L-Pages are stored in the non-volatile memory, wherein the entry is associated with at least one L-Page among the one or more L-Pages.
10. A storage system comprising:
a non-volatile memory; and
a controller;
wherein the controller is configured to:
receive an atomic write command;
store, based on the atomic write command, data in one or more logical pages (L-Pages), wherein each L-Page among the one or more L-Pages is associated with a logical address;
generate a system journal (S-Journal) entry for each of the one or more L-Pages, wherein each S-Journal entry comprises a first sequence number associated with the atomic write command;
determine, based on the S-Journal entries, whether all L-Pages are stored in a non-volatile memory;
after a power loss event, when all L-Pages are not determined to be stored in the non-volatile memory,
determine, based on the first sequence number, the minimum L-Page number and the maximum L-Page number, a range of L-Page numbers;
for each L-Page number in the range of L-Page numbers, determine data in the L-Page associated with the L-Page prior to receiving the atomic write command; and
generate a copy command to store the data, for the L-Pages associated with the range of L-Page numbers, in the non-volatile memory.
11. The storage system of claim 10 , comprising:
a volatile memory; and
wherein the controller is configured to:
for each of the one or more L-Pages:
store, in the volatile memory, an entry that specifies a physical address in the non-volatile memory that is associated with the logical address of the L-Page.
12. The storage system of claim 10 , wherein each S-Journal entry associates one or more physical pages to the L-Page.
13. The storage system of claim 10 , comprising:
a power-safe memory; and
wherein the controller is configured to:
store a second sequence number in the power-safe memory.
14. The storage system of claim of claim 13 , wherein the controller is configured to:
determine whether the first sequence number comprised in the S-Journal entry matches the second sequence number; and
when the first sequence number is determined to match the second sequence number,
determine that all L-Pages are not stored in the non-volatile memory.
15. The storage system of claim 13 , wherein the controller is configured to:
when the first sequence number is determined to match the second sequence number,
determine that all L-Pages are stored in the non-volatile memory.
16. The storage system of claim 10 , wherein the controller is configured to:
for each L-Page stored in the non-volatile memory:
determine whether an L-Page number associated with the L-Page is less than a minimum L-Page number comprised in an entry in a data structure;
when the L-Page number associated with the L-Page is determined to be less than the minimum L-Page number,
update the minimum L-Page number comprised in the entry with the L-Page number associated with the L-Page, wherein the entry is associated with the first sequence number associated with the atomic write command;
determine whether the L-Page number associated with the L-Page is greater than a maximum L-Page number comprised in the entry; and
when the L-Page number associated with the L-Page is determined to be greater than the maximum L-Page number,
update the maximum L-Page number comprised in the entry with the L-Page number associated with the L-Page.
17. The storage system of claim 10 , wherein the controller is configured to:
when all L-Pages are not determined to be stored in the non-volatile memory, defer an update to an entry in a logical-to-physical address translation map until all L-Pages are stored in the non-volatile memory, wherein the entry is associated with at least one L-Page among the one or more L-Pages.
18. The storage system of claim 10 , wherein the controller is configured to:
when all L-Pages are determined to be stored in the non-volatile memory, update an entry in a logical-to-physical address translation map.
19. A system comprising:
means for receiving an atomic write command;
means for storing, based on the atomic write command, data in one or more logical pages (L-Pages), wherein each L-Page among the one or more L-Pages is associated with a logical address;
means for generating a system journal (S-Journal) entry for each of the one or more L-Pages, wherein each S-Journal entry comprises a first sequence number associated with the atomic write command;
means for determining, based on the S-Journal entries, whether all L-Pages are stored in a non-volatile memory; and
after a power loss event, in response to determining that all L-Pages are not stored in the non-volatile memory:
means for determining, based on the first sequence number, a minimum L-Page number, and a maximum L-Page number, a range of L-Page numbers;
for each L-Page number in the range of L-Page numbers, means for determining data in the L-Page associated with the L-Page prior to receiving the atomic write command; and
means for generating a copy command to store the data, for the L-Pages associated with the range of L-Page numbers, in the non-volatile memory.
20. The system of claim 19 , comprising:
in response to determining that all L-Pages are not stored in the non-volatile memory:
means for deferring an update to an entry in a logical-to-physical address translation map until all L-Pages are stored in the non-volatile memory, wherein the entry is associated with at least one L-Page among the one or more L-Pages.